• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.922-931
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• 1993

Boundary element method was used to solve heat conduction problem for predicting temperature distribution in grain storage bin. Temperature of grain in storage is one of the three main abiotic factors, besides the intergranular gas composition and the grain moisture content, that determine the keeping quality and control measures used to protect grain from insects and damaging microflora. Collecting the temperature data at various points in the storage bins at different time of the day over a period of time is one way of finding the temperature distribution, this method requires a lot of time, cost and labour and less efficient. However data so collected serve useful purpose of being used to validate predicted temperature distribution using mathematical models. Mathematical models based on physical principles can potentially predict with accuracy the temperature distribution in a grain storage bin. Using the boundary element model the effect of bin wall material, ambient emperature, bin size etc. on temperature distribution can be studied. A knowledge of temperature distribution in stored grain not only helps in identifying active deterioration , but also gives an indication of potential for detection.

• Agricultural and Biosystems Engineering
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• 제1권1호
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• pp.49-53
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• 2000

A magnet assembly is a critical element of a nuclear magnetic resonance(NMR) based sensor. Magnetic flux density and homogeneity are essential to its optimum performance. Geometry and magnet material properties determine the magnetic flux density and homogeneity of the assembly. This study was carried out to develop the design for a magnet assembly. A 2-D finite element model for the magnetic assembly was developed using ANSYS and evaluated the effects of adding shimming frames and steel bars in the corners of the rectangular steel cover which surrounded the magnet. The assembly was manufactured and evaluated. According to the ANSYS model, modified pole frames increased magnetic flux density by 8.3% and increased homogeneity by 83%. Addition of steel bars in the corners increased the magnetic flux density by 1%, and improved homogeneity up to three times. The difference between simulated and measured magnetic flux densities at the center point of the air gap was within 2.4%.

• 한국정보통신학회논문지
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• 제19권11호
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• pp.2703-2709
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• 2015

IT 와 농업분야의 융합은 생산, 유통, 소비 분야에서의 효율과 질적 향상을 기대하게 되었고 특히 IT 영역의 정보 분석 기술과 자동제어 기술은 농산물 생산에 많은 장점을 제공하게 되었다. 네트워크 기반에서의 농업 분야 ICT확대는 기술적, 환경적인 측면에서의 어려움들을 해결하게 되었다. 본 논문에서는 IT와 접목한 스마트 농업 환경에서의 표준 기능 모델을 제안 분석하고 이를 바탕으로 한 스마트 농업에서의 기술적 서비스 요구조건 을 제시한다.

• ETRI Journal
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• 제42권6호
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• pp.886-898
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• 2020

Unusual data patterns or outliers can be generated because of human errors, incorrect measurements, or malicious activities. Detecting outliers is a difficult task that requires complex ensembles. An ideal outlier detection ensemble should consider the strengths of individual base detectors while carefully combining their outputs to create a strong overall ensemble and achieve unbiased accuracy with minimal variance. Selecting and combining the outputs of dissimilar base learners is a challenging task. This paper proposes a model that utilizes heterogeneous base learners. It adaptively boosts the outcomes of preceding learners in the first phase by assigning weights and identifying high-performing learners based on their local domains, and then carefully fuses their outcomes in the second phase to improve overall accuracy. Experimental results from 10 benchmark datasets are used to train and test the proposed model. To investigate its accuracy in terms of separating outliers from inliers, the proposed model is tested and evaluated using accuracy metrics. The analyzed data are presented as crosstabs and percentages, followed by a descriptive method for synthesis and interpretation.

• Asian Journal of Innovation and Policy
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• 제10권1호
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• pp.68-89
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• 2021

The expansion of irrigated agricultural production can be appropriate for the southeast region in the U.S. as a climate change adaptation strategy. This study investigated the effect of supplemental development of irrigated agriculture on the regional economy by applying the supply side Georgia multiregional input-output (MRIO) model. For the analysis, 100% conversion of non-irrigated cultivable acreage into irrigated acreage for cotton, peanuts, corn, and soybeans in 42 counties of southwest Georgia is assumed. With this assumption, the difference in total net returns of production between the non-irrigation and irrigation method is calculated as input data of the Georgia MRIO model. Based on the information of a 95% confidence interval for each crop's average price, the lower and upper bounds of estimated results are also presented. The total impact of cotton production was $60 million with the range of $35 million to $85 million: The total impact of peanuts, soybeans, corn was $10.2 million (the range of $3.28 million to $23.7 million), $6.6 million (the range of $3.1 million to $10.2 million), $1.2 million (the range of -$6 million to $8.5 million), respectively.

• The Journal of Asian Finance, Economics and Business
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• 제8권8호
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• pp.583-592
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• 2021

This study examines social identity and self-identity as the antecedents of the theory of planned behavior (TPB) model in predicting purchase intention of certified coffee, whereas perceived trustworthiness (PT) is evaluated whether it directly affects intention and/or indirectly through attitude. In addition, ethics and luxury are investigated as the salient beliefs affecting attitude formation in this regard. A face-to-face survey was conducted with 727 coffee consumers in Thailand. Confirmatory factor analysis is applied to assess the adequacy of the model, followed by structural equation modeling to evaluate the hypotheses proposed for the relationships between constructs in an extended TPB model. The results confirm that self-identity is the most influential antecedent on attitude when compared to social identity, and attitude, in turn, is the strongest determinant in predicting purchase intention. PT has a direct positive effect on purchase intention, meanwhile, ethical, luxury beliefs, and PT are confirmed to portrait the attitude formation. As such the marketing campaigns can address manipulating consumers' beliefs on both ethical and luxury aspects as well as PT, along with consumers' social identity and self-identity to fortify a positive attitude toward certified coffee. Then the actual purchase behavior can be foreseen based on empirical evidence.

• The Journal of Asian Finance, Economics and Business
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• 제9권3호
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• pp.23-31
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• 2022

The study investigates the effect of trade openness on the economic growth of agricultural countries. The information of export, import, gross domestic product (GDP), Gross Fixed Capital Formation (GFCF), and population of 72 agrarian nations generated by the World Bank from 2011 until 2020 is used for data examination. Then, before panel data analysis, a preferred model is chosen from among common-effects, fixed-effects, and random effects. The best model turns out to be a fixed-effect model. The result reports that from 2011 to 2020; 16 out of 72 nations have succeeded in experiencing positive economic growth, the value of GFCF was US$ 2,859.04 billion, and later grew by 19 percent to US$ 3,393.73 billion, the population tends to increase continuously year by year, and 2 out of 72 countries experienced export plus import exceed their GDP. Moreover, trade openness is positively associated with economic growth, with a coefficient of 3.81. Besides that, an increase in GFCF may boost economic growth by approximately 3.32 percent. On the contrary, one percent additional population significantly delivers around 25.46 percent negative economic growth. To sum up, the higher intensity of products or services sold and bought abroad may enhance the economic performance.

• 한국환경농학회지
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• 제39권4호
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• pp.289-296
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• 2020

BACKGROUND: There is a need for a revolutionary method to overcome the problem of biochar, which has relatively low adsorption capacity for existing anion pollutants, along with collectively recycling fallen leaves, a kind of forest by-product. Therefore, the objective of this study was to prepare iron-decorated biochar derived from fallen leaves (Fe-FLB), and to evaluate their adsorption properties to Congo red (CR) as anionic dye. METHODS AND RESULTS: The adsorption properties of CR by fallen leaves biochar (FLB) and Fe-FLB were performed under various conditions such as initial CR concentration, reaction time, pH and dosage with isotherm and kinetic models. In this study, Fe-FLB prepared through iron impregnation and pyrolysis of fallen leaves contained 56.9% carbon and 6.3% iron. Congo red adsorption by FLB and Fe-FLB was well described by Langmuir model and pseudo second order model and the maximum adsorption capacities of FLB and Fe-FLB were 1.1 mg/g and 25.6 mg/g, respectively. In particular, it was found that the adsorption of CR was occurred by chemical adsorption process by the outer boundary layer of Fe-FLB. CONCLUSION: Overall, the production of Fe-FLB using fallen leaves and using it as an anion adsorbent is considered to be a way to overcome the problem of biochar with relatively low anion adsorption in addition to the reduction effect of waste.

• 한국환경농학회지
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• 제40권4호
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• pp.239-247
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• 2021

BACKGROUND: Enormous amounts of the wood biomass wastes have been produced through various wood processing. This study characterizes the surface characteristics of biomass powders of Cornus controversa (CC) and Quercus mongolica (QM) and investigates their removal efficiency and mechanism for Pb (II) in aqueous solution on which to base potential recycling alternative of the wood biomass. METHODS AND RESULTS: Batch experiments were conducted under different conditions of Pb concentrations, temperatures, time and solid/solution ratios. Adsorption isotherm of Pb by CC and QM biomass was explained significantly by the Langmuir model, indicating Pb was likely adsorbed on the monolayer of the surfaces. The adsorption kinetics were fitted significantly to the double first-order model consisting of rapid and slow steps. The respective rate constants (k1) of CC and QM for the rapid adsorption kinetic steps were 0.051 and 0.177 min^-1, and most of the sorption reactions proceeded rapidly within 6-20 minutes. The maximum adsorption quantities (q_max) of Pb were 17.25 and 23.47 mg/g for CC and QM, respectively. Thermodynamic parameters revealed that adsorption of Pb on the biomass of CC and QM was a spontaneous endothermic reaction. CONCLUSION(S): Results demonstrate that biomass wastes of CC and QM can be used as Pb adsorbents judging from adsorption isotherm, kinetics, and thermodynamic parameters.

• 한국응용곤충학회지
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• 제21권4호
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• pp.200-206
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• 1982

Distributed Time Delay의 개념을 응용하여 이화명나방의 발생시기를 예측할 수 있는 Phenological System Model을 구성하고 이의 타당성검정을 위해 기존 병해충발생예찰자료 및 일별 기상관측자료를 이용하여 본 해충의 1세대 경과에 소요되는 유효적산온도(DEL)와 Delay의 차수 K치를 산출한 후 이화명나방의 누적우화율곡선을 전자계산기로 Simulation 하였다. 그 결과 Model에 의해 추정된 1978년의 6개 선정지점의 누적우화율곡선은 실측 누적유살수비율곡선과 매우 유사하였으나 우화 초기 및 후기에 다소 편재하는 경향이 있었다. 한편 실측 $50\%$ 유살일과 Model에 의해 추정된 $50\%$ 우화일 간에는 수원에서 6일, 춘천에서 $5\~6$일의 차이를 보였으나 이리, 대구, 보성 및 밀양지역에서는 $2\~3$일의 근소한 차이를 보였다. 이화명나방의 Phenological Simulation Model은 각 발육단계별 실측밀도조사자료와 월동후 유충집단의 발육 및 일령분포, 그리고 사망요인에 대한 고려 등이 연구 보완되어지므로 더욱 확장된 System으로서 구성되어 질 것으로 생각된다.